Merge commit 'upstream/master'

3 files changed, 45 insertions, 17 deletions

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 7084e7e146c0..5b78fd0aff0a 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -71,13 +71,6 @@ static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
                               dev->id.device, dev->id.vendor);
 }
 
-static struct bus_type virtio_bus = {
-        .name  = "virtio",
-        .match = virtio_dev_match,
-        .dev_attrs = virtio_dev_attrs,
-        .uevent = virtio_uevent,
-};
-
 static void add_status(struct virtio_device *dev, unsigned status)
 {
         dev->config->set_status(dev, dev->config->get_status(dev) | status);
@@ -120,12 +113,16 @@ static int virtio_dev_probe(struct device *_d)
                         set_bit(f, dev->features);
         }
 
+        /* Transport features always preserved to pass to finalize_features. */
+        for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
+                if (device_features & (1 << i))
+                        set_bit(i, dev->features);
+
         err = drv->probe(dev);
         if (err)
                 add_status(dev, VIRTIO_CONFIG_S_FAILED);
         else {
-                /* They should never have set feature bits beyond 32 */
-                dev->config->set_features(dev, dev->features[0]);
+                dev->config->finalize_features(dev);
                 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
         }
         return err;
@@ -147,13 +144,20 @@ static int virtio_dev_remove(struct device *_d)
         return 0;
 }
 
+static struct bus_type virtio_bus = {
+        .name  = "virtio",
+        .match = virtio_dev_match,
+        .dev_attrs = virtio_dev_attrs,
+        .uevent = virtio_uevent,
+        .probe = virtio_dev_probe,
+        .remove = virtio_dev_remove,
+};
+
 int register_virtio_driver(struct virtio_driver *driver)
 {
         /* Catch this early. */
         BUG_ON(driver->feature_table_size && !driver->feature_table);
         driver->driver.bus = &virtio_bus;
-        driver->driver.probe = virtio_dev_probe;
-        driver->driver.remove = virtio_dev_remove;
         return driver_register(&driver->driver);
 }
 EXPORT_SYMBOL_GPL(register_virtio_driver);
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index eae7236310e4..c7dc37c7cce9 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -94,12 +94,17 @@ static u32 vp_get_features(struct virtio_device *vdev)
         return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
 }
 
-/* virtio config->set_features() implementation */
-static void vp_set_features(struct virtio_device *vdev, u32 features)
+/* virtio config->finalize_features() implementation */
+static void vp_finalize_features(struct virtio_device *vdev)
 {
         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 
-        iowrite32(features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
+        /* Give virtio_ring a chance to accept features. */
+        vring_transport_features(vdev);
+
+        /* We only support 32 feature bits. */
+        BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
+        iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
 }
 
 /* virtio config->get() implementation */
@@ -297,7 +302,7 @@ static struct virtio_config_ops virtio_pci_config_ops = {
         .find_vq        = vp_find_vq,
         .del_vq         = vp_del_vq,
         .get_features   = vp_get_features,
-        .set_features   = vp_set_features,
+        .finalize_features = vp_finalize_features,
 };
 
 /* the PCI probing function */
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 72bf8bc09014..6eb5303fed11 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -18,6 +18,7 @@
  */
 #include <linux/virtio.h>
 #include <linux/virtio_ring.h>
+#include <linux/virtio_config.h>
 #include <linux/device.h>
 
 #ifdef DEBUG
@@ -87,8 +88,11 @@ static int vring_add_buf(struct virtqueue *_vq,
         if (vq->num_free < out + in) {
                 pr_debug("Can't add buf len %i - avail = %i\n",
                          out + in, vq->num_free);
-                /* We notify *even if* VRING_USED_F_NO_NOTIFY is set here. */
-                vq->notify(&vq->vq);
+                /* FIXME: for historical reasons, we force a notify here if
+                 * there are outgoing parts to the buffer.  Presumably the
+                 * host should service the ring ASAP. */
+                if (out)
+                        vq->notify(&vq->vq);
                 END_USE(vq);
                 return -ENOSPC;
         }
@@ -320,4 +324,19 @@ void vring_del_virtqueue(struct virtqueue *vq)
 }
 EXPORT_SYMBOL_GPL(vring_del_virtqueue);
 
+/* Manipulates transport-specific feature bits. */
+void vring_transport_features(struct virtio_device *vdev)
+{
+        unsigned int i;
+
+        for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
+                switch (i) {
+                default:
+                        /* We don't understand this bit. */
+                        clear_bit(i, vdev->features);
+                }
+        }
+}
+EXPORT_SYMBOL_GPL(vring_transport_features);
+
 MODULE_LICENSE("GPL");